Iraqi National Journal of Earth Science

This study covered most of Kolosh Formation exposure areas in northern Iraq. Description of the lithology and measuring the actual thickness of the Formation from exposures and well logs were performed. The isopach map of the Formation was constructed. The sedimentation of the Formation was affected by the tectonic activity of the northeastern edge of the Arabian plate during the closure of the Neo-Tethys Ocean. The tectonic setting outlined the depozone of foreland basin system and controlled the variation of the deposits of the Kolosh Formation along the orogenic front (It revealed that there are more than one basin of deposition). The deviations of the depocenters of the Kolosh deposit basins from the current folds are depicted. The counterclockwise rotation of Arabian plate and its oblique collision with Iranian plate as well as the rejuvenation of the basement faults during the peak of the orogeny might cause such deviation.

The biostratigraphy of Tanjero Formation has been investigated within a wellexposed
section at the northern limb of Perat anticline, Bekhme area, Northeastern Iraq.
The studied section consists mainly of marl, marly limestone, and sandstone. The
formation conformably overlies Shiranish Formation (Late Campanian-Maastrichtian)
and it is overlain unconformably by the Kolosh Formation (Paleocene). The samples of
the section under investigation yielded rich and well diversified planktonic foraminiferal
taxa, where 69 planktonic species belonging to 21 genera have been recognized. The
detailed foraminiferal investigation permits the recognition of four well defined zones.
These are from older at the base:
4. Plummerita hantkeninoides Total Range Zone.
3. Pseudoguembelina palpebra Partial Range Zone.
2. Pseudoguembelina hariaensis Interval Zone.
1. Racemiguembelina fructicosa Interval Zone.
The Planktonic zones were correlated with other zonal schemes in- and outside
Iraq. They are considered to be of Late Maastrichtian age.

Thirteen samples of Aaliji Formation from the well (K-116), Kirkuk area, Northern Iraq, are studied on the basis of the stratigraphic ranges of the recorded calcareous nannofossils for sixty species, the studied section reveals five biozones arranged from oldest to youngest as follows:
1. Fasciculithus tympaniformis Interval Biozone (CP4)
2. Heliolithus kleinpellii Interval Biozone (CP5)
3. Discoaster mohleri Interval Biozone (CP6)
4. Discoaster nobilis Interval Biozone (CP7)
5. Discoaster multiraditus Interval Biozone (CP8)
These biozones are correlated with other calcareous nannofossils biozones from both local and regional sections leading to conclude the age of Middle Paleocene to Early Eocene.

The application of apparent electrical conductivity (ECa) to agriculture is due to the soil salinity measurement, which represents a problem in arid areas associated with irrigated agricultural land and shallow aquifers.
The purpose of this paper is to apply the modern geo-referenced technology by using LandMapper ERM-02 device and GPS receiver to measure manually the soil ECa of (50) sites in the irrigated units N15 and N16 at Northern Al-Jazirah Irrigation Project. The remote sensing data, the map of Northern Al-Jazirah Irrigation Project and GIS are utilized to support the analysis and the spatial information of the measured ECa data. A kriging interpolation method is adopted to predict the ECa values at non-surveyed location and to create the final soil ECa map. The results of the field measurements show that the ECa in the study area varies between 2.66 to 51.74 dS/m. The results of the geostatistical analysis and the regression function of the ECa data indicate a decrease in the errors associated with the soil ECa interpolated map with increasing the values of soil ECa in the study area.
However, the studied method is less accurate than the laboratory based soil sample analysis method, but for a quick estimate of soil salinity, this method is highly satisfied.

Gercus Formation is exposed in northern Iraq. When the passive Arabian continental margin collided with the active continental margin of the Turkish and Iranian plates, a part of the source rocks of Gercus red beds were carried out from Iran and Turkey territories and deposited in the molasses trough, parallel to the suture zone of the collision, and the others were driving from the longitudinal paleo-high lying parallel to the trough basin of Gercus Formation.
The present study is based on three surface sections, Bekhme, Sarsank and Amadiya areas in Northern Iraq. Generally, the Gercus Formation consists of reddish brown to light grey, well bedded sandstones and mudstones in addition to thin beds of conglomerates. The most of sandstone particles are composed of polycrystalline and monocrystalline quartz (of metamorphic and plutonic origin), K and Na – feldspar (derived from igneous and metamorphic source rocks), and chert grains of sedimentary source. Carbonate and other rock fragments with low ratio of mica group and heavy minerals (magnetite and rutile) are present too.
The sandstones of Gercus Formation, generally contain low-moderate quantities of clay as matrix in all sections, therefore, they are texturally immature. On the other hand, the low ratio of quatrz and chert to feldspar and other components indicates to mineralogically immature sandstones. According to McBride classification, it is sublith arenite - Lithic arenite sandstone. Petrographic analysis of sandstones in Bekhme section revealed that it consist of variable amount of detritus, represented by the abundance of quartz and chert rock fragments with low content of feldspar, and at Sarsank and Amadiya sections, the Gercus sandstones are characterized by the abundant chert rock fragments with high percentage of metamorphic rock fragments. So they lay in the recycled provenance source of collision orogen.

The current study is based on the use of statistical techniques to study and identify factors controlling the concentrations of dissolved major elements in Tigris River water within a wide range of the river course, starting from Fishkabur region in the north to Baghdad city in the south.
The Results show that the rock compositions of the river basin mainly control the concentrations of the dissolved major ions in the river water with limited effect of anthropogenic factor, represented by human activities, that controls the nitrate ion concentration. The results also indicate the presence of spatial and temporal variations in the dissolved major ions concentrations, along the study area.

The present research includes a biostratigraphic study of calcareous nannofossils of the lower part of Balambo Formation (Lower Cretaceous) in Azmir anticline - northeastern Iraq. Lithologically, the lower part of the studied section (Balambo Formation) consists of limestone containing nodules of chert, marly limestone, with intercalations of green and gray-blue shale. In this work, it has been relied on calcareous nannofossils assamblages in biostratigaphy and age determination of this part because it does not contain planktonic foraminifera. First occurrences (FOs) and last occurrences (LOs) of marker species were used to identify biozones. The section was divided into four main biozones and two subzones and its correlation with collection from global, regional, and local biozones. Thus, the age of this part of the formation extends from the Late Early Hauterivian - Late Aptian. These are from older to younger:
1- Speetonia colligata Interval Zone (part)
2- Lithraphidites bollii Interval Zone
3- Micrantholithus hoschulzii Partial range Zone
4- Chiastozygus litterarius Interval Zone
Hayesites irregularis Interval Subzone
Eprolithus floralis Interval Subzone (part)

The study of the structural geology and tectonics of Qara Sard anticline and Goblagh syncline is carried out within the northwestern part of Zagros Fold-Thrust Belt (ZFTB) in Sulaimaniya area, Kurdistan region, Iraq. Qamchuqa Formation (Early Cretaceous) builds up the core of the anticline and overlain by Kometan, Shiranish and Tanjero formations (Late Cretaceous). Moreover, Khalakan Formation overlies Kometan Formation on the northeastern limb of the anticline. Tanjero Formation appears at the core of Choplagh syncline. The structural geometrical analyses of seven traverses (P) cutting across the anticline and the syncline, revealed that the two folds are double plunging, and asymmetrical in all traverses except in P5 and P6 in Qara Sard anticline. Both folds are verging toward northeast; however, the anticline verges toward southwest and being vertical in P4 and P5 respectively. The geometrical analysis using PI diagrams reveal that the fold axis of Qara Sard anticline is sinuous and changing its trend in three attitudes. The first is NW-SE in the traverses P1, P2 and P3 with gradual clockwise drifting. The second one is WNW-ESE in P4, P5 and P6 and then returning in the third to the first attitude NW-SE in the traverse P7. Consequently, the area was influenced by four strike-slip faults. They are either transverse or inclined to the fold axis. These faults are Dolma Reza dextral, Choplagh sinistral, Lower Zab dextral and Dokan sinistral. They divided the area into four blocks moved in opposite directions depending on the strike-slip faults displacements. On the other hand, the study folds are affected by three reverse listric faults. They are suture-verged and parallel with the fold axis. Two of them affected the northeastern limb of Qara Sard anticline, whereas the third disturbed its southwestern limb. By investigations of the vertical changes of fold style, the reactivation of the suture listric fault (2) is detected. It appears as a rotational type so as its larger effect is on traverse P7 and its displacement is gradually reduced toward P4. Moreover, the reactivation time of this suture rotational listric fault was Turonian, it is reflected throughout verging change of the fault between Qamchuqa and Kometan formations in traverse P6.

Field surveys of electrical resistance are achieved in order to study the sub-base layer of the under constructive roads where the present study is conducted in six locations (Bardarash, Rovya, Mahalabyia 1 and 2, Al-Gwair and Bashiqa) based on the existence of projects for roads under construction by the Directorate of Roads and Bridges. Furthermore, Azimuthal resistivity survey is applied using Parker-Watson array with an electrode spacing and azimuth depending on road directions. Also a reverse surveys are performed on the same points of sounding.
The resistance ratios (Rd1, Rd2) are then calculated and represented as polar diagrams and cartesian curves. Moreover, analysis relationships are done between the phases, amplitudes, frequencies and their reflections. It is observed from the polar diagrams of the mean resistance values, there is a resistivity variation with the depths and directions of the spread. It is also noticed that there are changes of the Anisotropy Coefficient (AC) values reflecting the effect of the lithofacies contrasts of the sub-base layer belonging to the paving and compacting mechanism underneath the central point of the azimuthal survey. A comparison between AC and Homogeneity Indices (HI) are determined, and the latest values are detected using the standard deviation approach which is thought to reflect the dispersion of measured resistances due to the heterogeneity constitutes.

The phosphatic compounds in the phosphorites of Akashat Formation (Middle Paleocene) are mainly composed of francolite. The associated rocks (phosphatic limestone) consist of calcite and francolite. As well as, there are little amounts of dolomite, palygorskite, quartz and iron oxides. Francolite is composed of Ca, P, F and O, the tetrahedron SO4 and planar CO3 as CO3+F substitute PO4. Some of Na and Mg are substituted in both sites Ca(I) and Ca(II). F occupied its sites in the channel. Some F subsititute O in CO3 to form the pseudo-tetrahedron of CO3+F. The elements Si, Al, Mg, Fe and K represent the clay minerals; montmorillonite, palygorskite and sepiolite, as well as, quartz and iron oxides.
The geochemistry of phosphorite reflects the primary neoformation conditions of marine apatite (francolite) from calcium, phosphate and fluorine, in addition to the substitution of positive mono- and di- valance cations for calcium in Ca(I) in submarine mud of the oceanic floor. The phosphate deposits were exposed to winnowing and transporting by upwelling currents to the continental shelf area. This led the phosphatic deposits to be affected by early and late chemical and biochemical diagenetic processes, causing activities in substitution of cations for calcium in Ca(II) and carbonate, also, additional fluorine and sulfates for phosphate. The flow of continental water to near-shore area, whose content is magnesium leading to remineralization of clay minerals, (e.g. palygorskite and sepiolite from montmorillonite) by depleting magnesium from sea water, as well as the activity of microorganism, all that is provided by suitable growth conditions for phosphatic compounds in continental shelf area.